Various technologies have been applied to the so-called Electronic Article Surveillance (EAS) marketplace. EAS “tags” are commonly used to control inventory in a retail sales environment. For example, a store selling expensive leather coats may attach EAS tags to each coat to prevent theft.
EAS systems invariably use one or more of three different basic schemes. Some tags are, for example, Radio Frequency (RF) based. These devices operate by detecting a radio signal reradiated by a resonant marker in response to a field applied to a designated interrogation zone.
Still other systems include electromagnetic markers (EM) that may, for example, make use of magneto-restrictive elements. Such types of EAS systems are based on markers that include a thin strip or wire of magnetic material that responds to an alternating interrogation signal by generating a signal pulse at a higher harmonic of the interrogation signal.
Still further systems may make use of other types of radiation, such as acousto-magnetic (AM) energy.
Thus EAS tags have been developed that use various types of radiation, including RF, EM and AM, for operation.
Certain prior art identification bands have been made tamper proof by including a disabling wire in the band. For example, in a co-pending U.S. patent application Ser. No. 10/400,049 on Mar. 26, 2003 by Girvin, J., and Lerch, J., entitled “Non-Reusable Identification Device”, assigned to Proximities, Inc., the assignee of the present application, a disabling wire is run along the band and is connected to disable a transponder if the wire is cut. Thus, the band of material must remain intact for the identification function to operate.